arXiv subjects

Murman Margvelashvili

Publications and source records attributed to Murman Margvelashvili.

3 recordsLinked to original sources

arXiv1995

On the Flavor Dependence of the Mixed Quark-Gluon Condensate

The flavour dependence of the mixed quark-gluon condensate is studied through the analysis of correlators of the hybrid current $a_μ=g\bar sγ_ργ_5 G_{ρμ}d$. The flavour symmetry breaking for this type of condensates is found to be less than that for the quark condensates. For the ratio of strange to nonstrange condensates we obtain \mbox{$R=0.95\pm 0.15$}. For the kaon coupling to the current $a_μ$ we find $δ'^2=(0.020\pm0.005)GeV^2$, which is an order of magnitude smaller than analogous chirally unsuppressed coupling.

hep-ph↗

arXiv1994

Estimating Condensates from the Difference of Tau Branching Fractions

The difference of tau partial decay widths into even and odd number of pions may be considered as another important constraint on the hadronic spectral function, in addition to four classic sum rules of current algebra. Within certain reasonable assumptions its value may be used to test the factorization hypothesis and estimate the contribution of dimension 6 condensates into the tau hadronic decay width.

hep-ph↗

arXiv1994

Determination of QCD Condensates Without Hadronic Spectra

The bounds on the values of gluon, four-quark and quark-gluon condensates are derived from the requirement of consistency of the sum rules for various correlators of the hybrid current $a_μ=g\bar dγ_ρ\tilde G_{ρμ}u$. The upper bound for the gluon condensate is found to be less then twice its standard value while for the four-quark condensates the violation of factorization by a factor 3-4 is allowed. The value of the quark-gluon condensate is given as a function of $\left<\frac{α_s}π G^2\right>$ and $\left<(\bar qΓq)^2\right >$ which for the standard values yields $m_0^2=0.63~\mbox{GeV}^2$ . Our procedure of simultaneous solution of a number of sum rules allows the quantitative error analysis and is appropriate for condensate determination also in other cases.

hep-ph↗